Information processing apparatus, program, and operation control me

ABSTRACT

There is provided an information processing apparatus including: a detection unit for detecting pressure applied by user input performed on a touch screen; a determination unit for determining which of two or more input states the user input belongs to, in accordance with the pressure detected by the detection unit; and an operation control unit for enabling or disabling a limitation imposed on operation with a user interface displayed on the touch screen, in accordance with the state of the user input determined by the determination unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and is based upon and claims thebenefit of priority under 35 U.S.C. § 120 from U.S. patent applicationSer. No. 15/647,757, filed Jul. 12, 2017, which is a continuation ofU.S. patent application Ser. No. 15/221,020, filed Jul. 27, 2016 (nowU.S. Pat. No. 9,710,158, issued Jul. 18, 2017), which is a continuationof Ser. No. 13/190,854, filed Jul. 26, 2011 (now U.S. Pat. No.9,547,436, issued Jan. 17, 2017), and claims the benefit of priorityunder 35 U.S.C. § 119 of Japanese Patent Application No. 2010-185072,filed Aug. 20, 2010; the entire contents of each of which areincorporated herein by reference.

BACKGROUND

The present disclosure relates to an information processing apparatus, aprogram, and an operation control method.

In recent years, various devices having touch screens are widely used. Atouch screen is also referred to as a touch panel, which achieves twofunctionalities, i.e., display and input, on one screen. One advantageof touch screens is intuitive operationality. Unlike a mouse, akeyboard, a keypad, or other pointing devices, a user who uses the touchscreen can directly touch a manipulation target displayed on the screen,and can manipulate the manipulation target.

However, one drawback of the touch screen is a difficulty in expandinguser input. For example, when a mouse is used, user input may beexpanded by adding input means such as buttons and wheels to the mouse.When a keyboard or a keypad is used, there may be as many differenttypes of user inputs as at least the number of keys. However, when thetouch screen is used, manipulation object is a simple tool such as afinger or a stylus. Accordingly, in many cases, it is more or lessdifficult to provide an additional component to the manipulation object.

In order to solve such issues, Japanese Patent Application Laid-Open No.2008-192092 suggests a technique for associating and registeringpatterns of touch pressure waveforms or pressure distributions detectedby a touch screen with various processings, and loading registeredprocessing in accordance with an input pattern.

SUMMARY

However, some user inputs are accompanied with another user input. And,while a main user input is performed on a touch screen, it is not easyfor a user to reproduce a particular pressure waveform or pressuredistribution for additional user input registered in advance, asdescribed in the technique of Japanese Patent Application Laid-Open No.2008-192092.

One example is that, when a straight line is drawn by dragging a mousein some graphic editor, the drawing direction can be limited to adirection of an integral multiple of 90 degrees (or 45 degrees) bydragging the mouse with pressing down a particular key (such as a SHIFTkey or a CTRL key). In this case, the accompanying additional userinput, i.e., pressing down of the particular key, is performed while themain user input, i.e., dragging of the mouse, is performed. When a touchscreen is used, it is possible to draw a straight line by dragging.However, it is difficult to reproduce a particular pressure waveform orpressure distribution while a straight line is drawn by dragging. When auser needs to perform input operation outside of the touch screen suchas pressing down a particular key while drawing a straight line, theintuitive operationality unique to the touch screen is spoiled, and theadvantage of using the touch screen is lost. This kind of additionaluser input is often used to change a setting of limitation of userinterface operated by a main user input as explained in the aboveexample of a graphic editor.

In light of the foregoing, it is desirable to provide a novel andimproved information processing apparatus, program, and operationcontrol method, capable of easily changing, on a touch screen, a settingof limitation imposed on a user interface.

According to an embodiment of the present disclosure, there is providedan information processing apparatus including: a detection unit fordetecting pressure applied by user input performed on a touch screen; adetermination unit for determining which of two or more input states theuser input belongs to, in accordance with the pressure detected by thedetection unit; and an operation control unit for enabling or disablinga limitation imposed on operation with a user interface displayed on thetouch screen, in accordance with the state of the user input determinedby the determination unit.

The determination unit may determine which of two or more input statesthe user input belongs to by comparing the pressure with a thresholdvalue.

The information processing apparatus may further include: a display unitfor displaying, on the touch screen, the state of the user inputdetermined by the determination unit.

The user interface may be a graphical user interface with which a userspecifies a parameter.

The limitation may be a limitation imposed on a granularity of a valueof the parameter that can be specified.

The parameter may be a parameter for an amount of scroll of a contentdisplayed on the touch screen.

The parameter may be a parameter for a numerical value.

The parameter may be a parameter for a selection range of a contentdisplayed on the touch screen.

The parameter may be a parameter for a position or a size of an objectdisplayed on the touch screen.

When the pressure is determined to be more than the threshold value, thedetermination unit may determine that the user input belongs to a firstinput state, and thereafter, until a predetermined condition issatisfied, the determination unit may determine that a subsequent userinput also belongs to the first input state.

The predetermined condition may include releasing of a manipulationobject from the touch screen.

The predetermined condition may include elapse of a certain period oftime.

The predetermined condition may include a condition that the pressureonce becomes less than the threshold value and thereafter becomes morethan the threshold value.

According to an embodiment of the present disclosure, there is provideda program for causing a computer that controls an information processingapparatus to function as: a detection unit for detecting pressureapplied by user input performed on a touch screen; a determination unitfor determining which of two or more input states the user input belongsto, in accordance with the pressure detected by the detection unit; andan operation control unit for enabling or disabling a limitation imposedon operation with a user interface displayed on the touch screen, inaccordance with the state of the user input determined by thedetermination unit.

The determination unit may determine which of two or more input statesthe user input belongs to by comparing the pressure with a thresholdvalue.

The program may cause the computer to further function as a display unitfor displaying, on the touch screen, the state of the user inputdetermined by the determination unit.

The user interface may be a graphical user interface with which a userspecifies a parameter.

The limitation may be a limitation imposed on a granularity of a valueof the parameter that can be specified.

When the pressure is determined to be more than the threshold value, thedetermination unit may determine that the user input belongs to a firstinput state, and thereafter, until a predetermined condition issatisfied, the determination unit may determine that a subsequent userinput also belongs to the first input state.

According to an embodiment of the present disclosure, there is providedan operation control method including: detecting pressure applied byuser input performed on a touch screen; determining which of two or moreinput states the user input belongs to, in accordance with the detectedpressure; and enabling or disabling a limitation imposed on operationwith a user interface displayed on the touch screen, in accordance withthe determined state of the user input.

As described above, according to the information processing apparatus,the program, and the operation control method according to the presentdisclosure, a setting of limitation imposed on a user interface can beeasily changed on a touch screen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of hardwareconfiguration of an information processing apparatus according to anembodiment;

FIG. 2 is a block diagram illustrating an example of logicalconfiguration of an information processing apparatus according to anembodiment;

FIG. 3 is an explanatory diagram illustrating a first example of inputstate determination processing according to an embodiment;

FIG. 4 is an explanatory diagram illustrating a second example of inputstate determination processing according to an embodiment;

FIG. 5 is an explanatory diagram illustrating a third example of inputstate determination processing according to an embodiment;

FIG. 6 is an explanatory diagram illustrating a fourth example of inputstate determination processing according to an embodiment;

FIG. 7 is an explanatory diagram illustrating a first example of GUIaccording to an embodiment;

FIG. 8 is an explanatory diagram illustrating a second example of GUIaccording to an embodiment;

FIG. 9 is an explanatory diagram illustrating a third example of GUIaccording to an embodiment;

FIG. 10 is an explanatory diagram illustrating a fourth example of GUIaccording to an embodiment;

FIG. 11 is an explanatory diagram illustrating a fifth example of GUIaccording to an embodiment;

FIG. 12 is an explanatory diagram illustrating a sixth example of GUIaccording to an embodiment;

FIG. 13 is an explanatory diagram illustrating a first example ofdisplays of input states according to an embodiment;

FIG. 14 is an explanatory diagram illustrating a second example ofdisplays of input states according to an embodiment;

FIG. 15 is an explanatory diagram illustrating a third example ofdisplays of input states according to an embodiment;

FIG. 16 is an explanatory diagram illustrating a fourth example ofdisplays of input states according to an embodiment; and

FIG. 17 is a flowchart illustrating an example of flow of operationcontrol processing according to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

Hereinafter, “DETAILED DESCRIPTION OF THE EMBODIMENTS” will be describedin detail in the order listed below.

1. Exemplary configuration of apparatus

2. Examples of input state according to pressure

3. Examples of user interface

4. Examples of display of input state

5. Examples of flow of processings

6. Conclusion

1. Exemplary Configuration of Apparatus

An information processing apparatus explained in this specification istypically an apparatus having a touch screen. For example, theinformation processing apparatus may be a PC (Personal Computer), asmart phone, a PDA (Personal Digital Assistant), a music player, a gameterminal or a digital household appliance. Alternatively, theinformation processing apparatus may be a peripheral device connected tothese devices.

(1) Hardware Configuration

FIG. 1 is a block diagram illustrating an example of hardwareconfiguration of an information processing apparatus 100 according tothe present embodiment. As shown in FIG. 1, the information processingapparatus 100 includes a touch screen 20, a bus 30, a CPU (CentralProcessing Unit) 32, a ROM (Read Only Memory) 34, and a RAM (RandomAccess Memory) 36.

The touch screen 20 includes a touch detection surface 22 and a displaysurface 24. The touch detection surface 22 detects touch operation by auser on the touch screen 20, and generates an electric signalrepresenting pressure of the touch and the touched position. Forexample, the touch detection surface 22 is formed according to any touchdetection method such as a resistive film method, a surface acousticwave method, or an electrostatic method. The display surface 24 displaysan output image given by the information processing apparatus 100. Forexample, the display screen 24 is implemented using liquid crystal,organic EL (Organic Light-Emitting Diode: OLED), or CRT (Cathode RayTube).

The bus 30 connects the touch detection surface 22, the display surface24, the CPU 32, the ROM 34 and the RAM 36 with each other.

The CPU 32 controls overall operations in the information processingapparatus 100. The ROM 34 stores data and programs constituting softwareexecuted by the CPU 32. The RAM 36 temporarily stores the data and theprograms during execution of the processings by the CPU 32.

Although explanation is omitted here for the sake of brevity ofexplanation, the information processing apparatus 100 may includeconstituent elements other than those depicted in FIG. 1.

(2) Logical Configuration

FIG. 2 is a block diagram illustrating an example of logicalconfiguration of the information processing apparatus 100 according tothe present embodiment. As shown in FIG. 2, the information processingapparatus 100 includes a touch detection unit 110, a display unit 120, adetermination unit 130, an operation control unit 140, and anapplication unit 150.

The touch detection unit 110 detects a user input as a touch operationon the touch screen 20. Then, the touch detection unit 110 outputsinformation including the touched position and the pressure value, i.e.,attributes of the detected user input, to the determination unit 130 andthe operation control unit 140 in the order of time.

The display unit 120 uses the display surface 24 of the touch screen 20to display the output image provided by the information processingapparatus 100. For example, the output image displayed by the displayunit 120 may include an application screen generated by the applicationunit 150 explained later. Further, the output image displayed by thedisplay unit 120 may include a screen of an operating system (not shown)of the information processing apparatus 100. Still further, these outputimage may include an image of a graphical user interface (GUI)controlled by the operation control unit 140.

The determination unit 130 determines which of two or more input statesa user input belongs to, in accordance with pressure detected by thetouch detection unit 110.

In this specification, examples of two or more input states include anenabled state and a disabled state of limitation imposed on operationwith user interfaces. For example, limitation of drawing direction fordrawing a straight line by drag operation is one of limitations imposedon operation with user interfaces. In this example, in the enabled stateof limitation, for example, the drawing direction can be limited to adirection of an integral multiple of 90 degrees (i.e., four directionsincluding upward, downward, left, and right). On the other hand, in thedisabled state of limitation, any drawing direction can be specified.The enabled state of limitation may include a plurality of states. Forexample, there may be a third input state in which the drawing directionis limited to a direction of an integral multiple of 45 degrees (i.e.,eight directions including upward, downward, left, right, upper right,lower right, upper left, and lower left).

For example, the determination unit 130 compares the latest pressure(i.e., currently input pressure) with a threshold value set in advance,whereby the determination unit 130 may determine which of two or moreinput states the user input belongs to. For example, when the pressureis determined to be more than the threshold value, the determinationunit 130 may determine that the user input belongs to the first inputstate. Thereafter, until a predetermined condition is satisfied, thedetermination unit 130 may determine that subsequent user inputs alsobelong to the first input state. In this specification, the lattermethod is referred to as “lock” of input state. A specific example ofinput state determination processing with this kind of determinationunit 130 will be further detailed below.

The operation control unit 140 enables or disables limitation imposed onoperation with a user interface displayed on the touch screen 20 inaccordance with an input state determined by the determination unit 130.For example, when the latest pressure is equal to or less than thethreshold value, this state is referred to as the first input state, andwhen the latest pressure is more than the threshold value, this state isreferred to as the second input state. That is, it is assumed that thefirst input state is defined as a state in which limitation is enabled,and the second input state is defined as a state in which limitation isdisabled. Under these presumptions, when user input is given with a lowpressure (equal to or less than the threshold value), the operationcontrol unit 140 controls operation with user interface with limitation.On the other hand, when user input is given with a high pressure (morethan the threshold value), the operation control unit 140 controlsoperation with user interface upon deactivating the limitation. Aspecific example of user interface whose operation is controlled by theoperation control unit 140 will be further detailed below.

The application unit 150 provides application functions to the user ofthe information processing apparatus 100. For example, the applicationunit 150 includes one or more of a Web browser, a digital album, adocument editor, an email client, a content player, and a gameapplication. For example, the user can use these application functionsvia a GUI controlled by the operation control unit 140 according topressure.

2. Examples of Input State According to Pressure

Subsequently, a specific example of input state determination processingwith the determination unit 130 according to the present embodiment willbe explained with reference to FIGS. 3 to 6. FIGS. 3 to 6 areexplanatory diagrams each illustrating an example of input statedetermination processing performed with the determination unit 130. Thegraph in the upper part of each figure represents a pressure valueobtained by detection with the touch detection unit 110 along a temporalaxis. On the other hand, determination results of input statesdetermined by the determination unit 130 in accordance with the pressurevalues detected by the touch detection unit 110 are shown under eachgraph.

(1) First Example

In the first example (FIG. 3) of the input state determinationprocessing, the determination unit 130 compares a latest pressure valueP with a threshold value P_(th) set in advance, thereby determiningwhich of input states ST1 and ST2 a user input belongs to. As shown inFIG. 3, in the period when a time T is equal to or less than T₁, thepressure value P is equal to or less than the threshold value P_(th).Accordingly, the determination unit 130 determines that the user inputduring this period belongs to the input state ST1. Subsequently, in theperiod when the time T is more than T₁ but is equal to or less than T₂,the pressure value P is more than the threshold value P_(th).Accordingly, the determination unit 130 determines that the user inputduring this period belongs to the input state ST2. Further, in theperiod when the time T is more than T₂, the pressure value P is equal toor less than the threshold value P_(th) again. The determination unit130 determines that the user input during this period belongs to theinput state ST1. As a result, for example, in the period when the time Tis equal to or less than T₁ and the period when the time T is more thanT₂, the limitation imposed on the operation with user interface can beenabled. In the period when the time T is more than T₁ but is equal toor less than T₂, the limitation can be disabled (or vice versa).

In this case, the threshold value P_(th) may be set in a fixed manner,or may be dynamically changed. For example, a different threshold valueP_(th) may be set in advance for each user who logs into the informationprocessing apparatus 100. Alternatively, the threshold value P_(th) maybe dynamically determined on the basis of an average value of sampledpressures applied by users.

(2) Second Example

FIGS. 4 to 6 are explanatory diagrams each illustrating an example oflocking of input state. In the second example of input statedetermination processing, when the pressure value P is determined to bemore than the threshold value P_(th), the determination unit 130determines that the input state is the input state ST2. Thereafter,until a manipulation object is released from the touch screen 20, thedetermination unit 130 determines that subsequent user inputs belong tothe input state ST2. As shown in FIG. 4, in the period when a time T isequal to or less than T₃, the pressure value P is equal to or less thanthe threshold value P_(th). Accordingly, the determination unit 130determines that the user input during this period belongs to the inputstate ST1. Thereafter, when the time T is equal to the time T₃, thepressure value P attains a value more than the threshold value P_(th).Accordingly, in a period from this point of time to when a user releasesa finger or other manipulation object from the touch screen 20, thedetermination unit 130 determines that, even if the pressure value P isless than the threshold value P_(th), the user input during this periodbelongs to the input state ST2. As shown in FIG. 4, when the time T isequal to T₄, the pressure value P becomes zero, at which it isrecognized that the user releases the manipulation object from the touchscreen 20. Therefore, the user input in the period when the time T ismore than T₄ is determined to belong to the input state ST1 again.

Since the input state is locked as described above, the user can operatethe user interface in such a manner that the limitation enabled by theexisting setting is disabled (or the limitation disabled by the existingsetting is enabled) without forcing the user to constantly operate thetouch screen 20 with a high pressure during drag operation.

(3) Third Example

In the third example, when the pressure value P is determined to be morethan the threshold value P_(th), the determination unit 130 determinesthat the input state is the input state ST2. Thereafter, until apredetermined period of time passes, the determination unit 130determines that subsequent user inputs belong to the input state ST2. Asshown in FIG. 5, in the period when the time T is equal to or less thanT₃, the pressure value P is equal to or less than the threshold valueP_(th). Accordingly, the determination unit 130 determines that the userinput during this period belongs to the input state ST1. Thereafter,when the time T is equal to the time T₃, the pressure value P attains avalue more than the threshold value P_(th). Accordingly, in a periodfrom this point of time to when a certain period of time dT passes, thedetermination unit 130 determines that, even if the pressure value P isless than the threshold value P_(th), the user input during this periodbelongs to the input state ST2. As shown in FIG. 5, at a time T=T₃+dT,the input state determined by the determination unit 130 returns fromthe input state ST2 to the input state ST1.

(4) Fourth Example

In the fourth example, when the pressure value P is determined to bemore than the threshold value P_(th), the determination unit 130determines that the input state is the input state ST2. Thereafter, fromwhen the pressure value P becomes less than the threshold value P_(th)and to when the pressure value P becomes more than the threshold valueP_(th) again, the determination unit 130 determines that subsequent userinputs belong to the input state ST2. As shown in FIG. 6, in the periodwhen the time T is equal to or less than T₃, the pressure value P isequal to or less than the threshold value P_(th). Accordingly, thedetermination unit 130 determines that the user input during this periodbelongs to the input state ST1. Thereafter, when the time T is equal tothe time T₃, the pressure value P attains a value more than thethreshold value P_(th). Accordingly, in a period after this point oftime, the determination unit 130 determines that, even if the pressurevalue P is less than the threshold value P_(th), the user input duringthis period belongs to the input state ST2. As shown in FIG. 6, thepressure value P temporarily decreases to a value less than thethreshold value P_(th) once, and then when the time T is equal to T₅,the pressure value P attains a value more than the threshold valueP_(th) again. Therefore, the user input in the period when the time T ismore than T₅ is determined to belong to the input state ST1 again.

According to the lock release method shown in FIG. 5 or 6, a user caneasily switch enabled/disabled state of limitation imposed on operationwith user interface in a series of operations without once releasing themanipulation object from the touch screen 20.

3. Examples of User Interface

Subsequently, six examples of GUIs controlled by the operation controlunit 140 according to the present embodiment will be explained withreference to FIGS. 7 to 12.

(1) First Example

The first example shown in FIG. 7 is an example of GUI with which a userspecifies an amount of scroll in a screen. The limitation of the GUI inthe first example is a limitation for limiting scroll direction to oneof a plurality of directions.

As shown in the left part of FIG. 7, a Web page 11 showing news articlesis displayed on the touch screen 20. The Web page 11 can be scrolled inthe vertical and horizontal directions. In this case, when a user dragsa finger 5 on the touch screen 20, the Web page 11 scrolls in thedragged direction. However, the scroll direction of the Web page 11 islimited to only the vertical direction in the input state ST1. On theother hand, the scroll direction of the Web page 11 is not limited inthe input state ST2. In the input state ST2, it may also be possible toscroll in the horizontal direction.

As shown in the upper right of FIG. 7, the user drags the finger 5 to alower right corner on the touch screen 20 in the input state ST1, sothat the Web page 11 is scrolled upward (not scrolled in the upper leftdirection). In other words, the above limitation is enabled. On theother hand, as shown in the lower right of FIG. 7, the user drags thefinger 5 to a lower right corner on the touch screen 20 in the inputstate ST2, so that the Web page 11 is scrolled in the upper leftdirection.

(2) Second Example

The second example shown in FIG. 8 is an example of GUI with which auser specifies a parameter value in a predetermined range. Thelimitation of the GUI in the second example is a limitation for limitingthe number of specifiable parameter values to a limited number ofcandidate values.

As shown in the left of FIG. 8, an image 12 and a slider 13 aredisplayed on the touch screen 20. The slider 13 is a GUI for specifyinga zoom ratio of the image 12. When a user drags a knob of the slider 13,the zoom ratio of the image 12 is changed according to the position ofthe dragged knob. However, in the input state ST1, the zoom ratio can bespecified as only four types of values, i.e., 100%, 75%, 50% or 25%. Onthe other hand, in the input state ST2, the zoom ratio can be specifiedas any value ranging from 1% to 100%.

As shown in the upper right of FIG. 8, the user drags the knob of theslider 13 in the input state ST1, so that the image 12 is displayed witha zoom ratio of 50%. On the other hand, as shown in the lower right ofFIG. 8, the user drags the knob of the slider 13 to the same position inthe input state ST2, so that the image 12 is displayed with a zoom ratioof 40%.

(3) Third Example

The third example shown in FIG. 9 is also an example of GUI with which auser specifies a parameter value. Like the second example, thelimitation of the GUI in the third example is a limitation for limitingthe number of specifiable parameter values to a limited number ofcandidate values.

In FIG. 9, a drop-down list 14 is displayed on the touch screen 20 toallow a user to specify a font size of text. The user can specify a fontsize corresponding to a touched position by touching a position in alist of the drop-down list 14. However, in the input state ST1, thevalues that can be specified are only those shown in the list. On theother hand, in the input state ST2, values not shown in the list canalso be specified according to a touched position.

As shown in the left of FIG. 9, the user touches a position in a list ofthe drop-down list 14 in the input state ST1, whereby font size 16 pt isselected. On the other hand, as shown in the right of FIG. 9, the usertouches the same position in the list of the drop-down list 14 (theposition between 16 and 18 in the list) in the input state ST2, wherebyfont size 17 pt is selected. For example, the value of the font size inthe input state ST2 is determined by interpolating the value of the fontsize, on the basis of the touched position and a position of a label(for example, central position) of a font size shown in the list.

(4) Fourth Example

The fourth example shown in FIG. 10 is an example of GUI with which auser specifies a parameter of a selection range of text displayed on thetouch screen 20. The limitation of the GUI in the fourth example is alimitation for setting a selection range of text not in units ofcharacters but in units of words.

In the left of FIG. 10, a text 15 is displayed on the touch screen 20.The user drags any position of the text 15, whereby a rangecorresponding to the dragged position can be selected. However, theselection range is set in units of words in the input state ST1. On theother hand, in the input state ST2, the selection range is set in unitsof characters, i.e., the minimum unit.

As shown in the center and the right in the upper row of FIG. 10, theuser drags the text 15 in the input state ST1, whereby the selectionrange 16 is set in units of words. On the other hand, as shown in thecenter and the right in the lower row of FIG. 10, the user drags thetext 15 in the input state ST2, whereby the selection range 16 is set inunits of characters.

(5) Fifth Example

The fifth example shown in FIG. 11 is an example of GUI with which auser specifies a parameter of a size of an object displayed on the touchscreen 20. The limitation of the GUI in the fifth example is alimitation for maintaining an aspect ratio when a size of an object ischanged.

In the left of FIG. 11, an object 17 is shown that may be displayed onthe touch screen 20. For example, the user pinches out or pinches in twofingers on the object 17 (in other words, while one of the two fingersis fixed on the object 17, the other of the two fingers is draggedthereon), whereby the size of the object 17 can be enlarged or reduced.However, in the input state ST1, the aspect ratio of the object 17 ismaintained. On the other hand, in the input state ST2, the aspect ratioof the object 17 is not maintained, and the shape of the object 17 canbe changed in accordance with an enlargement ratio in a verticaldirection and an enlargement ratio in a horizontal direction which aredifferent from each other.

As shown in the upper right of FIG. 11, the user pinches out the fingerson the object 17 in the input state ST1, whereby the object 17 isenlarged while the aspect ratio is maintained. On the other hand, asshown in the lower right of FIG. 11, the user pinches out the fingers onthe object 17 in the input state ST2 in the same manner, whereby theobject 17 is enlarged in the vertical direction.

For example, the pressure compared with the threshold value in the fifthexample may be higher one of pressures respectively applied by twofingers, or may be a mean value of pressures applied by two fingers.

(6) Sixth Example

The sixth example shown in FIG. 12 is an example of GUI with which auser specifies a parameter of a position of an object displayed on thetouch screen 20. The limitation of the GUI in the sixth example is alimitation for aligning a position of an object with a grid.

In the left of FIG. 12, a grid 18 and an object 19 are displayed on thetouch screen 20. For example, the user drags the object 19, so that theobject 19 can be moved. However, in the input state ST1, the position ofthe object 19 is arranged at a limited position defined by the grid 18.On the other hand, in the input state ST2, the position of the object 19is not limited to the position defined by the grid 18.

As shown in the upper right of FIG. 12, the user drags the object 19 inthe input state ST1, whereby the object 19 is aligned with the positiondefined by the grid 18. On the other hand, as shown in the lower rightof FIG. 12, the user drags the object 19 in the input state ST2 in thesame manner, whereby the object 19 is moved to the specified positionwithout relying on the grid 18.

In the example of GUI described with reference to FIGS. 7 to 12,limitation is enabled/disabled with operation with user interface on thetouch screen 20. Therefore, user input for enabling/disabling alimitation is preferably performed during a series of operationsperformed on the touch screen 20 without interfering with main operationwith user interface. In the present embodiment, limitation is enabled ordisabled in accordance with input state switched on the basis ofpressure applied by user input performed on the touch screen 20. In thiscase, change of pressure does not interfere with operation performed onthe touch screen 20, such as touch, drag, and pinch-in/pinch-out.Further, it is easy for a user to change the pressure during the aboveoperation. Therefore, as described in the present embodiment,enabling/disabling of limitation of GUI is controlled in accordance withthe pressure applied by user input, whereby the state of limitation canbe switched easily and quickly without losing the intuitiveoperationality unique to the touch screen.

Many of the examples of limitations explained above are limitation ofgranularity (the magnitude of the minimum unit of a value that can bespecified) of a parameter value that can be specified. In other words,when limitation is enabled, the granularity of the parameter value thatcan be specified is coarse, in which case even when user input is rough,an appropriate parameter value can be selected. On the other hand, whenthe limitation is disabled, the granularity of the parameter value thatcan be specified is fine, in which case the user can finely adjust theparameter value by himself/herself. Further, according to the presentembodiment, the user can intuitively switch the setting of granularityof such parameter value by changing the strength of touch operationwhile the user operates the user interface.

4. Examples of Display of Input State

In the present embodiment, the state of user input (the state of settingof limitation) determined by the determination unit 130 is displayed onthe touch screen 20 by the display unit 120 under the control of theoperation control unit 140. For example, the display unit 120 may changethe color or the shape of user interface of a manipulation target, ormay attach a certain character string or mark to the user interface ofthe manipulation target, whereby the state of user input can bedisplayed. For example, the display unit 120 may display the state ofuser input using a dedicated indicator provided independently from theuser interface of the manipulation target. FIGS. 13 to 16 areexplanatory diagrams illustrating examples of displays of the states ofuser inputs.

FIG. 13 also shows the scrollable Web page 11 shown in FIG. 7 as anexample. In FIG. 13, four arrows in up, down, right, and left directionsare displayed in proximity to a touched position of the Web page 11. Inthe state in which the scroll direction is limited to only the verticaldirection, the display unit 120 grays out, for example, the arrows inthe left and right directions among these arrows. On the other hand, inthe state in which the scroll direction is not limited, the display unit120 displays these four arrows in the same color with the same degree oftransparency.

FIG. 14 also shows the slider 13 shown in FIG. 8 as an example. Forexample, the display unit 120 enlarges and displays the knob of theslider 13 (see the left of FIG. 14), in the state in which limitation isimposed on the granularity of the zoom ratio that can be specified. Onthe other hand, for example, the display unit 120 reduces and displaysthe knob of the slider 13 (see the right of FIG. 14), in the state inwhich limitation is not imposed on the granularity of the zoom ratiothat can be specified.

FIG. 15 also shows the object 17 whose size can be changed as shown inFIG. 11 as an example. For example, the display unit 120 displays anauxiliary object 17 a extending along sides outside of the right sideand the lower side of the object 17 (see the left of FIG. 15), in thestate in which the aspect ratio of the size to be changed is maintained(i.e., the limitation is enabled). On the other hand, for example, thedisplay unit 120 does not display the auxiliary object 17 a (see theleft of FIG. 15), in the state in which the aspect ratio of the size tobe changed is not maintained.

FIG. 16 also shows the movable object 19 shown in FIG. 12 as an example.For example, the display unit 120 displays the grid 18 (see the left ofFIG. 16), in the state in which the position of the object 19 is alignedwith the grid (i.e., limitation is enabled). On the other hand, forexample, the display unit 120 does not display the grid 18 (see the leftof FIG. 16), in the state in which the object 19 can be moved to anyposition.

As described above, the display unit 120 displays the state of userinput on the touch screen 20, so that the user can easily understandwhether limitation imposed on operation with user interface is currentlyenabled or not. Therefore, the user can appropriately switch the stateof limitation by changing the pressure.

5. Examples of Flow of Processings

FIG. 17 is a flowchart illustrating an example of flow of operationcontrol processing performed by the information processing apparatus 100according to the present embodiment.

As shown in FIG. 17, first, the touch detection unit 110 detects touchoperation, i.e., user input, performed on the touch screen (step S102).Then, the touch detection unit 110 outputs information including thepressure and touched position thus detected to the determination unit130 and the operation control unit 140.

Subsequently, the determination unit 130 determines which of two or moreinput states the user input belongs to, in accordance with pressuredetected by the detection unit 110 (step S104). For example, thedetermination unit 130 compares the latest pressure value with thethreshold value set in advance, thereby determining which of inputstates ST1 and ST2 a user input belongs to. For example, thedetermination unit 130 may lock the input state or may release the lockof the input state in accordance with change of the pressure.

Subsequently, the operation control processing is branched in accordancewith the current input state (step S106). For example, when the inputstate is currently the input state ST1, the operation control unit 140enables the limitation and controls the user interface (step S108). Onthe other hand, when the current input state is the input state ST2, theoperation control unit 140 disables the limitation and controls the userinterface (step S110).

Naturally, it should be understood that the present embodiment is notlimited to the example of FIG. 17. Alternatively, the limitation may beenabled when the current input state is the input state ST2. Stillalternatively, the operation control processing may be branched intoprocessings for three or more input states.

6. Conclusion

The embodiment of the present disclosure has been hereinabove explainedwith reference to FIGS. 1 to 17. According to the present embodiment,determination is made as to which of two or more input states a userinput belongs to, in accordance with pressure applied by user inputperformed on a touch screen. Accordingly, limitation imposed onoperation with user interface is enabled or disabled in accordance withthe determined input state. Therefore, a user can easily change, on thetouch screen, the setting of limitation imposed on operation with userinterface.

Further, according to the present embodiment, the input state isdetermined on the basis of the comparison between the pressure value andthe threshold value. Accordingly, without disturbing main operation, theuser can switch the state of limitation easily and quickly by increasing(or decreasing) the strength of the pressure during the main operationon which limitation is to be imposed. Further, since a user can changepressure during main operation, it is easy for the user to be remindedof the operation for switching the limitation by comparing it with otherkinds of operations even when the user does not remember the operationfor switching the limitation.

Further, according to the present embodiment, the state of user input isdisplayed on the touch screen. Therefore, the user can easily understandwhether limitation imposed on operation with user interface is currentlyenabled or not.

The user interface to which the present embodiment may be appliedincludes graphical user interface with which a user specifies parameters(such as numerical values, positions, sizes, directions, and ranges). Ingeneral, limitations are imposed on parameters in advance when theparameters are specified, and this eliminates the necessity of fineadjustment made by a user and increases the convenience of theapplication in many cases. However, in some cases, a userhimself/herself may want to make fine adjustment. Even in such a case,according to the method of the present embodiment, the user can easilychange the state of limitation of operation for specifying a parameterwithout losing the advantage of the touch screen, i.e., intuitiveoperationality.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-185072 filed in theJapan Patent Office on Aug. 20, 2010, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. An electronic device comprising: a touch screen;a pressure sensitive sensor configured to detect pressure applied byuser inputs with a manipulation object performed on the touch screen;and circuitry configured to determine which of two or more input statesa first user input of the user inputs belongs to by comparing thedetected pressure with a threshold value for a predetermined time;determine that the first user input belongs to a first input state ofthe two or more input states when the detected pressure is determined tobe more than the threshold value for the predetermined time; determinethat a second user input of the user inputs after the first user inputis in the first input state until the pressure is determined to be equalto or less than the threshold value after the determination that thedetected pressure of the first user input is more than the thresholdvalue for the predetermined time; and determine that a third user inputof the user inputs is in a second input state of the two or more inputstates after releasing of the manipulation object from the touch screen.2. The electronic device of claim 1, wherein the circuitry configured toenable a limitation in the first input state.
 3. The electronic deviceof claim 2, wherein the limitation is to limit for selecting an item. 4.The electronic device of claim 3, wherein the limitation is to limit anumber of specifiable parameter values to a limited number of candidatevalues.
 5. The electronic device of claim 1, wherein the electronicdevice is one of a personal computer, a smart phone, a music player, agame terminal or a digital household appliance.
 6. The electronic deviceof claim 1, wherein the circuitry is configured to control a display todisplay a screen corresponding to at least one of a web browser, adigital album, a document editor, an email client, a content player or agame application.
 7. A method performed by an electronic deviceincluding a touch screen and a pressure sensitive sensor configured todetect pressure applied by user inputs with a manipulation objectperformed on the touch screen, the method comprising: determining whichof two or more input states a first user input of the user inputsbelongs to by comparing the detected pressure with a threshold value fora predetermined time; determining that the first user input belongs to afirst input state of the two or more input states when the detectedpressure is determined to be more than the threshold value for thepredetermined time; determining that a second user input of the userinputs after the first user input is in the first input state until thepressure is determined to be equal to or less than the threshold valueafter the determination that the detected pressure of the first userinput is more than the threshold value for the predetermined time; anddetermining that a third user input of the user inputs is in a secondinput state of the two or more input states after releasing of themanipulation object from the touch screen.
 8. The method of claim 7,further comprising: enabling a limitation in the first input state. 9.The method of claim 8, wherein the limitation is to limit for selectingan item.
 10. The method of claim 9, wherein the limitation is to limit anumber of specifiable parameter values to a limited number of candidatevalues.
 11. The method of claim 7, wherein the electronic device is oneof a personal computer, a smart phone, a music player, a game terminalor a digital household appliance.
 12. A non-transitory computer-readablemedium including computer-program instructions, which when executed byan electronic device including a touch screen and a pressure sensitivesensor configured to detect pressure applied by user inputs with amanipulation object performed on the touch screen, cause the electronicdevice to: determine which of two or more input states a first userinput of the user inputs belongs to by comparing the detected pressurewith a threshold value for a predetermined time; determine that thefirst user input belongs to a first input state of the two or more inputstates when the detected pressure is determined to be more than thethreshold value for the predetermined time; determine that a second userinput of the user inputs after the first user input is in the firstinput state until the pressure is determined to be equal to or less thanthe threshold value after the determination that the detected pressureof the first user input is more than the threshold value for thepredetermined time; and determine that a third user input of the userinputs is in a second input state of the two or more input states afterreleasing of the manipulation object from the touch screen.
 13. Thenon-transitory computer-readable medium of claim 12, wherein thecomputer-program instructions, which when executed by the electronicdevice, cause the electronic device to: enable a limitation in the firstinput state.
 14. The non-transitory computer-readable medium of claim13, wherein the limitation is to limit for selecting an item.
 15. Thenon-transitory computer-readable medium of claim 14, wherein thelimitation is to limit a number of specifiable parameter values to alimited number of candidate values.
 16. The non-transitorycomputer-readable medium of claim 12, wherein the electronic device isone of a personal computer, a smart phone, a music player, a gameterminal or a digital household appliance.
 17. The non-transitorycomputer-readable medium of claim 12, wherein the computer-programinstructions, which when executed by the electronic device, cause theelectronic device to: control a display to display a screencorresponding to at least one of a web browser, a digital album, adocument editor, an email client, a content player or a gameapplication.